Tire-pump.



W. S. STAPLEY.

TIRE PUMP.

A APPLICATION FILED APR.19, 1909. 947,5 1 3, Patented Jan. 25, 1910.

-ffy 7., Z5/f l l I l l@ I I l l .J7 w @l :U Grmmw UNITED STATES PATENT @FETCH WILLIAM S. STAELEY, OF BRIDGEPORT, CONNECTICUT. ASSIGNOR TO BRIDGE- PORT BRASS COMPANY, OF BRIDGEPORT, CONNECTICUT, A CORPORATION 0F CONNECTICUT.

TIRE-PUMP.

Specification of Letters Patent.

Patented Jan. 25, 1910.

Application filed April 19. 1909. Serial No. 490,835.

To all whom it 'mo/y concern:

Be 1t known that I, WILLIAM S. STAPLEY,

l threaded upper portion of the wall of recess a citizen of the United States, residing at t Bridgeport, county of Fairfield, State of specification,-`

has its lower end clamped in its recess in the base. while the washer and the circular rib 1lb constitute a tight joint.

The sn'lallcylinder 'l'is similarly formed lwitli an outwardly turned flange 15, a

This invention 'relates to air pumps of the i type generally used for intlating pneumatic tires by hand, and has particular reference to such pumps of the double acting compound type in which two parallel cylinders of ditterent sizes are secured together, the pistons and piston rods being Aconnected to work in unison, but in which the effective stroke of the two pistons tal'ies place in opposite directions as in Letters latent 855026 granted to me May 28, 1907. In said patent, however` the. cylinders are mounted one within the other.

The objects of my present invention are to provide an improved pump of the ty e referred to, in a simplified, cheapene and practical form Aand the parts of which may be easily assembled.

To these ends the invention consists in the construction and combination of parts substantially as hereinafter' described and claimed.

Of the accompanying drawings :-Figure l. is an elevation, partlyin section, of a pump embodying my present. invention, the middle portion being Ibroken away to reduce the height of the figure.. Fig. 2 is a plan view of a portion of the base removed. `Fig. 3 is a detail sectional view through the cap and the upper portion of the small cylinder. n Similar reference characters indicate the same or similar parts in all ofthe views.

The base 10 having suitable lateral portions or wings. on which the foot or feet of ,the user maybear, is 'formed with two circular recesses 11 and 12.,.the latter being smaller than the former. The large recess 11 isformed with a shoulder 11, a circular rib 11b Arising from said shoulder. The

lsmaller recess 12 is also formed with a shoulder 12a and e circuler rib 12". The two recesses areconnected by a port 13.

The' vlarge cylinder l14 is formed with an outwardly turned flange 14, and a washer l14" is.cor'npressed between said 4flange and the shouldered rib, by means of a nut 14e, which is threaded to it a correspondingly washer 15b heilig clamped between said flange and the ribbed shoulder below it by means of a nut 15 fitting a threaded portion of the wall of the recess 12.

The upper end ot' the cylinder 15 enters a recess in the underside ot cap 16 which is preferably a casting. No tighft joint is needed at the upper end of the large cylinder.

The two piston rods are indicated at 17 and 18, said piston rods v assing through the cap and through a tie p ate 19 which bears on the under side of the handle 20, said piston rods also preferably passing through the handle and having nuts 17"L and 18u secured to their upper ends above the handle. The piston rods are provided respectively with pistons 2l and 22 secured to their lower ends. Said piston rods have their cup-shaped flexible members turned in opposite directions, said cup-shaped members being held between two disks one 0f which bears against a should-er of the )iston rod and the other disk being clampeil in place by a nut on the threaded lower end of the piston rod. The shoulders of the two pis ton rods are located at dilerent heights so that the'piston on' the rod `18 will be located in a lower plane than the piston 2l. This in order that, in the upstroke, the top disk of the piston 2l will contact with the cap 16 before the piston 22 can be raised high enough to have its vflexible member injured by contact with said ca The extreme lower end of the rod 17 1s elongated as at 17b to form a stop which, by contact with the bottom of'recess 11, will limit the downward movement so as to prevent injury to either piston.

The 4upper end ott' the small cylinder 15 is externally threaded as at 23, thls thread being shown as a lefthand thread, it being understood that the thread of the nut 15 is a right-hand thread. If the end 23 has a right-hand thread, then the nut 15c will be left-hand threaded. The reason 'for' this will be presently described.

By means of said nut the large cylinder with the use of any gasket, litharge, or

. solder. The reason for the reverse thread arrangement above described is that when the parts are being assembled, there is so much friction between thenut 15c and the flanged-lower end of the cylinder 15, that said nut and cylinder are likely to be turned together as one. By the reverse thread ar-v rangement, rotation in the proper direction draws the cap and base toward each other so thatboth lends of the cylinder 15 will be firmly seated.

The piston rod 18, above the cup 24, passes through the only stuing box that the pump requires, sai stuiing box comprising a nut and a washer 26. rlhe cap 16 isformed with an out-let port 27, the

A* outer end of which is provided with a check valve 28, said port then communicating-with a nozzle 29 to whichl a suitable hose 30 may bc connected.' A stop screw 31 is provided tor the check valve. Also a nipple pipe 32 which leads to a pressure gage 33. This structure of-check valve and stop screw' and nozzle and pressure' gage may be substantially the same as in my Patent 855,026 before referred to.

The supply of air to the larger cylinder may be varound its upper end or around the upper end of the piston rod 17, as no tight joints need be formed at these points. Or a small hole may be provided as indicated at 34.

In operation, down stroke of the two pistous forces air lfrom the large cylinder through port 13 and around piston 22 into the small cylinder from which it may escape through port 27 if. the resistance is. not too great in the tire which is `being inflated. During this down stroke air enters the large cylinder above the piston 21. On the up l claim is stroke, 'the air above the small piston is forced out through 27. While the vacuum produced in the small cylinder below the up-l wardly moving piston 22 results inY drawing air fromv the large cylinder past the piston 21 and through port 13,'as has been stated the upper disk of'the piston 21 strikes the. .cap 16 in time to prevent injury to the flexible member of the small piston, while on the down stroke, the. end 17 b of piston 17 strikes the bottom of recess 11 in time to prevent injury to the flexible member of piston 21.

Having nowl described my invention, what 1. A pump comprising a base having two recesses which are internally threaded, said recesses having also internal shoulders each having anupwardly projecting rib, washers mounted on said shoulders, cylinders having outwardly turned flanges bearing on said washers, and nuts engagingthe threads of the recesses and clamping theflanges of the cylinders on said Washers.

2. A pump having a base provided with-a shouldered recess, a cylinder having a flange at its lower end, a washer interposed between the flange and shoulder, and means for clamping the flange of the cylinder against said washer.

. A pump including in its construction a cylinder, a metal cup fitting partly within the cylinder, a recessed -member into which said cylinder and its cup extend, and means for forcing the said member and cylinder together to cause thecup to expand the endof the cylinder.v

4. A pump including in its construction a cylinder having an externally threaded end, a cap havinga threaded recess for said cylinder, a tapered metal cup fitting partly within the end of `the cylinder and havingits` edge bearing on the end of the recess, anda piston and piston rod the latter passing through said cup.

In testimony whereof l affix my signature in presence of' two witnesses.

WILLIAM S. STAPLE Y. 

